ok so my dad just went through 6 injectors on his 2005 cummins, the engine temperature gauge sorta worked before the injectors and now it is pegged all the time, we unplugged the temp sensor and nothing changed.

since this thing was brand new the temp gauge would peg when cold and start working normally after the engine warmed up it also changes the timing and it starts like crap in the morning, it is a salvage truck, and it was wrecked hard on the drivers side, the wire blocks that plug into the fuse box are crunched up and do not fit properly.... the problem might be there, in the comp, in the gauge, ANYWHERE!

so please help pinpoint the problem it is driving us insane...

 

I would start first at fixing the crunched connectors. If the temp gauge is shorting out, chances are good that other circuits will do the same. Go to a bone yard and get the connectors off another truck. Then solder and shrink wrap the new connectors onto your harness. Make your connections at differant levels so your bundle isn't too big.

If it's just the temp gauge, I would just install an autometer and be done with it.